Metalcore Breakdown Composer is a bizarrely marketed app for, one presumes, composing a combination of Metal and Dubstep. The only screenshot available for the app is a splash screen, the iTunes description is a bit thin, and the iTunes "support" link goes to a fucking Facebook page. All of that said, they have a very well produced promo video.

Metalcore Breakdown Composer iTunes Description:

You like Metalcore? You like Breakdowns? Then you will love this app. Show your friends what you listen to and make Breakdowns like your favorite Metalcore-Band. You can choose between 6 different drum-sounds from evil to modern, which build the basic of your breakdown-session. With 12 different special sounds (Voice, FX, GuitarFX) you can customize your Breakdowns parts.

6 basic guitar sounds makes your session perfect and will make your friends to do some crazy crabcore-moves! Promise!